Pen



FIG. 1 is a front elevational view of a pen showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a side elevational view thereof from the left of FIG. 1;

FIG. 4 is a side elevational view thereof from the right of FIG. 1;

FIG. 5 is a perspective view thereof;

FIG. 6 is an enlarged view thereof from the bottom of FIG. 3; and,

FIG. 7 is an enlarged view thereof from the top of FIG. 3. 

The ornamental design for a pen, as shown and described. 